The gerbil, Gerbillus gerbillus, a nocturnal desert rodent of northern Africa, exhibits a seasona... more The gerbil, Gerbillus gerbillus, a nocturnal desert rodent of northern Africa, exhibits a seasonal reproductive cycle with marked anatomical and behavioural shifts between breeding season and resting season. The aim of this study is to investigate key elements involved in these seasonal changes, specifically in males: the histology of the testis as well as the expression of the G‐protein‐coupled oestrogen receptor 1 (GPER1) in the testis. During the breeding season, the seminiferous tubules were full of spermatozoa, and their epithelium contained germinal cells embedded in Sertoli cells. Amidst tubules, well‐developed Leydig cells were observed around blood vessels, with peritubular myoid cells providing structural and dynamic support to the tubules. GPER1 was largely expressed throughout the testis. Notably, Leydig cells, spermatogonia and spermatocytes showed strong immunohistochemical signals. Sertoli cells, spermatozoa and peritubular myoid cells were moderately stained. During ...
Animals are used for scientific purposes across Africa to benefit humans, animals or the environm... more Animals are used for scientific purposes across Africa to benefit humans, animals or the environment. Nonetheless, ethical and regulatory oversight remains limited in many parts of the continent. To strengthen this governance framework, the Pan-African Network for Laboratory Animal Science and Ethics brought together experts from 12 African countries to create an Africa-centric practical guide to facilitate the establishment and appropriate functioning of Institutional Animal Ethics Committees across Africa. The Guidelines are based on universal principles for the care and use of sentient animals for scientific purposes, with consideration of the cultural, religious, political and socio-economic diversity in Africa. They focus on 11 key elements, including responsibilities of institutions and of the Institutional Official; composition of the Committee; its responsibilities, functioning and authority; ethical application and review processes; oversight and monitoring of animal care a...
Methylglyoxal is a dicarbonyl compound recruited as a potential cytotoxic marker, initially prese... more Methylglyoxal is a dicarbonyl compound recruited as a potential cytotoxic marker, initially presents in cells and considered as a metabolite of the glycolytic pathway. Our aim is to demonstrate the inhibitory effect of 3, 3'-[3-(5-chloro-2-hydroxyphenyl)-3-oxopropane-1, 1-diyl] Bis (4-hydroxycoumarin) on the glyoxalase system, and indirectly its anticancer activity. The docking of OT-55 was conducted by using Flexible docking protocol, ChiFlex and libdock tools inside the active site of Glo-I indicated that both hydrogen bonding and hydrophobic interactions contributed significantly in establishing potent binding with the active site which is selected as a strong inhibitor with high scoring values and maximum Gibbs free energy. Coumarin-liposome formulation was characterized and evaluated in vivo against chemically induced hepatocarcinoma in Wistar rats. After Diethylnitrosamine (DEN) induction, microscopic assessment was realized; precancerous lesions were developed showing an increase of both tumor-associated lymphocyte and multiple tumor acini supported by the blood investigation. Our finding also suggested a preferential uptake of liposomes respectively in liver, kidney, lung, brain and spleen in the DEN-treated animals. OT-55 has also been shown to inhibit the activity of Glo-I in vitro as well as in DEN-treated rats. An abnormal high level of MGO of up to 50% was recorded followed by a reduction in glucose consumption and lactate dehydrogenase production validated in the positive control. MGO generates apoptosis as depicted by focal hepatic lesions. Also, no deleterious effects in the control group were observed after testing our coumarin but rather a vascular reorganization leading to nodular regenerative hyperplasia. Involved in the detoxification process, liver GSH is restored in intoxicated rats, while no changes are seen between controls. At the endothelial cell, OT-55 appears to modulate the release of NO only in the DEN-treated group. OT-55 would behave both as an anticancer agent but also as an angiogenic factor regarding results obtained.
Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a et... more Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a ete realisee sur deux especes de rongeurs deserticoles de la famille des gerbillides : Gerbillus gerbillus (nocturne granivore) et Psammomys obesus (diurne herbivore). Pour l’especes nocturne, la fonction testiculaire est caracterisee par un minimum en automne, une reprise en hiver, un maximum au debut du printemps et une regression en ete. Chez l’espece diurne, il existe un cycle saisonnier de la fonction endocrine du testicule, faible au printemps-ete et eleve en automne-hiver. La fonction thyroidienne de l’especes nocturne varie dans des proportions faibles et semble active tout au long de l’annee. La thyroide du rat des sables, espece diurne, est cependant, de moindre activite au printemps et en ete. Chez le rat des sables, les variations saisonnieres de la fonction thyroidienne semblent plus nettes.
Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a et... more Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a ete realisee sur deux especes de rongeurs deserticoles de la famille des gerbillides : Gerbillus gerbillus (nocturne granivore) et Psammomys obesus (diurne herbivore). Pour l’espece nocturne, la fonction testiculaire est caracterisee par un minimum en automne, une reprise en hiver, un maximum au debut du printemps et une regression en ete. Pour l’espece diurne, il existe un cycle saisonnier de la fonction endocrine du testicule, faible au printemps-ete et eleve en automne-hiver. La fonction thyroidienne de l’espece nocturne varie dans des proportions faibles et semble active tout au long de l’annee alors que celle du rat du sable, espece diurne, est de moindre activite au printemps et en ete. Chez le rat des sables, les variations saisonnieres de la fonction thyroidienne semblent plus nettes.
The molecular mechanisms operating on a seasonal time-scale and regulating functions such as repr... more The molecular mechanisms operating on a seasonal time-scale and regulating functions such as reproduction are poorly understood in animals living in desert environments. Kisspeptin, the product of the KiSS-1 gene, plays a critical role in control of the hypothalamic-pituitary-gonad axis that orchestrates the reproductive system in vertebrates. We report a sequence analysis of KiSS-1 and the pituitary luteinising hormone-beta (LHβ) and follicle-stimulating hormone-beta (FSHβ) in the Libyan jird (Meriones libycus), a seasonal breeding rodent that is sexually active during spring and quiescent in fall. We also assessed gene expression by quantitative real-time reverse transcription-polymerase chain reaction during the non-breeding and breeding seasons. The KiSS-1 cDNA sequence analysis showed high homology between M. libycus and all other rodents (94%) and humans (92%). KiSS-1 expression was higher during the breeding season than that during the non-breeding season. In contrast, LHβ an...
Two analytical methods; high performance liquid chromatography and gas chromatography were used t... more Two analytical methods; high performance liquid chromatography and gas chromatography were used to determine the content of 2-methylquinoxaline, a methylglyoxal-derived agent in sera from cattle with fascioliasis. Methylglyoxal is a highly mutagenic and cytotoxic reactive dicarbonyl compound formed by non-enzymatic fragmentation of triose phosphate GAP and DHAP during glycolysis which regularly contributes to repositioning the energetic balance between physiological and pathological situations. The aim of this study was to propose the MGO as a new biomarker in the bovine fasciolosis. Strongly infected animals showed a correlation between the relatively high levels of Fasciola hepatica anti-f2 antibody and methylglyoxal compared to unharmed animals. Also, an acute hyperglycemia was recorded and closely related to hepatic parenchyma hyperplasia, inflammation, bile ducts obstruction and scléro-fibrous foci formation.Unlike HPLC, which has shown analytical flaws and irregularities, GC-MS remains an excellent diagnostic tool for detecting and quantifying methylglyoxal in biological fluids. The developed method has been validated under FDA guidelines. A full scan-range was set from m/z 39 to 144/999 and the molecular weight of the 2-methylquinoxaline was identified according to NIST Database and ES. Methylglyoxal was the only analyte successfully quantified in a relatively short run time. It was linear over a concentration range of 0.057 to 5.7μg.ml-1with mean recoveries and RSD of 118% and 3.63% respectively. The intra and inter-day assays were satisfying and not exceed 3.00%. Results reflect the degree of precision of our method and indicate that MGO was an important contributor to understand the hepatic failure independently of other serum markers.
The gerbil, Gerbillus gerbillus, a nocturnal desert rodent of northern Africa, exhibits a seasona... more The gerbil, Gerbillus gerbillus, a nocturnal desert rodent of northern Africa, exhibits a seasonal reproductive cycle with marked anatomical and behavioural shifts between breeding season and resting season. The aim of this study is to investigate key elements involved in these seasonal changes, specifically in males: the histology of the testis as well as the expression of the G‐protein‐coupled oestrogen receptor 1 (GPER1) in the testis. During the breeding season, the seminiferous tubules were full of spermatozoa, and their epithelium contained germinal cells embedded in Sertoli cells. Amidst tubules, well‐developed Leydig cells were observed around blood vessels, with peritubular myoid cells providing structural and dynamic support to the tubules. GPER1 was largely expressed throughout the testis. Notably, Leydig cells, spermatogonia and spermatocytes showed strong immunohistochemical signals. Sertoli cells, spermatozoa and peritubular myoid cells were moderately stained. During ...
Animals are used for scientific purposes across Africa to benefit humans, animals or the environm... more Animals are used for scientific purposes across Africa to benefit humans, animals or the environment. Nonetheless, ethical and regulatory oversight remains limited in many parts of the continent. To strengthen this governance framework, the Pan-African Network for Laboratory Animal Science and Ethics brought together experts from 12 African countries to create an Africa-centric practical guide to facilitate the establishment and appropriate functioning of Institutional Animal Ethics Committees across Africa. The Guidelines are based on universal principles for the care and use of sentient animals for scientific purposes, with consideration of the cultural, religious, political and socio-economic diversity in Africa. They focus on 11 key elements, including responsibilities of institutions and of the Institutional Official; composition of the Committee; its responsibilities, functioning and authority; ethical application and review processes; oversight and monitoring of animal care a...
Methylglyoxal is a dicarbonyl compound recruited as a potential cytotoxic marker, initially prese... more Methylglyoxal is a dicarbonyl compound recruited as a potential cytotoxic marker, initially presents in cells and considered as a metabolite of the glycolytic pathway. Our aim is to demonstrate the inhibitory effect of 3, 3'-[3-(5-chloro-2-hydroxyphenyl)-3-oxopropane-1, 1-diyl] Bis (4-hydroxycoumarin) on the glyoxalase system, and indirectly its anticancer activity. The docking of OT-55 was conducted by using Flexible docking protocol, ChiFlex and libdock tools inside the active site of Glo-I indicated that both hydrogen bonding and hydrophobic interactions contributed significantly in establishing potent binding with the active site which is selected as a strong inhibitor with high scoring values and maximum Gibbs free energy. Coumarin-liposome formulation was characterized and evaluated in vivo against chemically induced hepatocarcinoma in Wistar rats. After Diethylnitrosamine (DEN) induction, microscopic assessment was realized; precancerous lesions were developed showing an increase of both tumor-associated lymphocyte and multiple tumor acini supported by the blood investigation. Our finding also suggested a preferential uptake of liposomes respectively in liver, kidney, lung, brain and spleen in the DEN-treated animals. OT-55 has also been shown to inhibit the activity of Glo-I in vitro as well as in DEN-treated rats. An abnormal high level of MGO of up to 50% was recorded followed by a reduction in glucose consumption and lactate dehydrogenase production validated in the positive control. MGO generates apoptosis as depicted by focal hepatic lesions. Also, no deleterious effects in the control group were observed after testing our coumarin but rather a vascular reorganization leading to nodular regenerative hyperplasia. Involved in the detoxification process, liver GSH is restored in intoxicated rats, while no changes are seen between controls. At the endothelial cell, OT-55 appears to modulate the release of NO only in the DEN-treated group. OT-55 would behave both as an anticancer agent but also as an angiogenic factor regarding results obtained.
Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a et... more Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a ete realisee sur deux especes de rongeurs deserticoles de la famille des gerbillides : Gerbillus gerbillus (nocturne granivore) et Psammomys obesus (diurne herbivore). Pour l’especes nocturne, la fonction testiculaire est caracterisee par un minimum en automne, une reprise en hiver, un maximum au debut du printemps et une regression en ete. Chez l’espece diurne, il existe un cycle saisonnier de la fonction endocrine du testicule, faible au printemps-ete et eleve en automne-hiver. La fonction thyroidienne de l’especes nocturne varie dans des proportions faibles et semble active tout au long de l’annee. La thyroide du rat des sables, espece diurne, est cependant, de moindre activite au printemps et en ete. Chez le rat des sables, les variations saisonnieres de la fonction thyroidienne semblent plus nettes.
Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a et... more Une etude comparative des variations saisonnieres des activites testiculaire et thyroidienne a ete realisee sur deux especes de rongeurs deserticoles de la famille des gerbillides : Gerbillus gerbillus (nocturne granivore) et Psammomys obesus (diurne herbivore). Pour l’espece nocturne, la fonction testiculaire est caracterisee par un minimum en automne, une reprise en hiver, un maximum au debut du printemps et une regression en ete. Pour l’espece diurne, il existe un cycle saisonnier de la fonction endocrine du testicule, faible au printemps-ete et eleve en automne-hiver. La fonction thyroidienne de l’espece nocturne varie dans des proportions faibles et semble active tout au long de l’annee alors que celle du rat du sable, espece diurne, est de moindre activite au printemps et en ete. Chez le rat des sables, les variations saisonnieres de la fonction thyroidienne semblent plus nettes.
The molecular mechanisms operating on a seasonal time-scale and regulating functions such as repr... more The molecular mechanisms operating on a seasonal time-scale and regulating functions such as reproduction are poorly understood in animals living in desert environments. Kisspeptin, the product of the KiSS-1 gene, plays a critical role in control of the hypothalamic-pituitary-gonad axis that orchestrates the reproductive system in vertebrates. We report a sequence analysis of KiSS-1 and the pituitary luteinising hormone-beta (LHβ) and follicle-stimulating hormone-beta (FSHβ) in the Libyan jird (Meriones libycus), a seasonal breeding rodent that is sexually active during spring and quiescent in fall. We also assessed gene expression by quantitative real-time reverse transcription-polymerase chain reaction during the non-breeding and breeding seasons. The KiSS-1 cDNA sequence analysis showed high homology between M. libycus and all other rodents (94%) and humans (92%). KiSS-1 expression was higher during the breeding season than that during the non-breeding season. In contrast, LHβ an...
Two analytical methods; high performance liquid chromatography and gas chromatography were used t... more Two analytical methods; high performance liquid chromatography and gas chromatography were used to determine the content of 2-methylquinoxaline, a methylglyoxal-derived agent in sera from cattle with fascioliasis. Methylglyoxal is a highly mutagenic and cytotoxic reactive dicarbonyl compound formed by non-enzymatic fragmentation of triose phosphate GAP and DHAP during glycolysis which regularly contributes to repositioning the energetic balance between physiological and pathological situations. The aim of this study was to propose the MGO as a new biomarker in the bovine fasciolosis. Strongly infected animals showed a correlation between the relatively high levels of Fasciola hepatica anti-f2 antibody and methylglyoxal compared to unharmed animals. Also, an acute hyperglycemia was recorded and closely related to hepatic parenchyma hyperplasia, inflammation, bile ducts obstruction and scléro-fibrous foci formation.Unlike HPLC, which has shown analytical flaws and irregularities, GC-MS remains an excellent diagnostic tool for detecting and quantifying methylglyoxal in biological fluids. The developed method has been validated under FDA guidelines. A full scan-range was set from m/z 39 to 144/999 and the molecular weight of the 2-methylquinoxaline was identified according to NIST Database and ES. Methylglyoxal was the only analyte successfully quantified in a relatively short run time. It was linear over a concentration range of 0.057 to 5.7μg.ml-1with mean recoveries and RSD of 118% and 3.63% respectively. The intra and inter-day assays were satisfying and not exceed 3.00%. Results reflect the degree of precision of our method and indicate that MGO was an important contributor to understand the hepatic failure independently of other serum markers.
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Papers by Farida Khammar